Simultaneously utilizing photogenerated electrons and holes to convert renewable biomass and its derivatives into corresponding value‐added products and hydrogen(H_(2))is a promising strategy to deal with the energy ...Simultaneously utilizing photogenerated electrons and holes to convert renewable biomass and its derivatives into corresponding value‐added products and hydrogen(H_(2))is a promising strategy to deal with the energy and environmental crisis.Herein,we report a facile hydrothermal method to construct a direct Z‐scheme CdS/WO_(3) binary composite for photocatalytic coupling redox reaction,simultaneously producing H_(2) and selectively converting aromatic alcohols into aromatic aldehydes in one pot.Compared with bare CdS and WO_(3),the CdS/WO_(3) binary composite exhibits significantly enhanced performance for this photocatalytic coupled redox reaction,which is ascribed to the ex‐tended light harvesting range,efficient charge carrier separation rate and optimized redox capabil‐ity of CdS/WO_(3) composite.Furthermore,the feasibility of converting various aromatic alcohols to corresponding aldehydes coupled with H_(2) evolution on the CdS/WO_(3) photocatalyst is proved and a reasonable reaction mechanism is proposed.It is hoped that this work can provide a new insight into the construction of direct Z‐scheme photocatalysts to effectively utilize the photogenerated electrons and holes for photocatalytic coupled redox reaction.展开更多
Photocatalytic oxidation of aromatic alcohol into aromatic aldehyde using O_(2)has received huge atten-tion,while the reaction that occurred in ambient air is rarely studied but follows the green-chemistry principles....Photocatalytic oxidation of aromatic alcohol into aromatic aldehyde using O_(2)has received huge atten-tion,while the reaction that occurred in ambient air is rarely studied but follows the green-chemistry principles.Herein,spindle-shaped MIL-53(Fe)-NH_(2)@ZnIn_(2)S_(4)photocatalysts with a Z-scheme heterostruc-ture were facilely developed for photocatalytic oxidation of aromatic alcohol in air under visible light.The benzyl alcohol conversion can be notably enhanced to 73%over the optimal MIL-53-NH_(2)@ZnIn_(2)S_(4)sample with a benzaldehyde production rate of 1825μmol g^(-1)h^(-1).However,in the O_(2)atmosphere,the benzyl alcohol conversion is only 56%,indicating that O_(2)is not required and has an adverse effect on the reaction.The hierarchical structure and Z-scheme heterojunction of MIL-53-NH_(2)@ZnIn_(2)S_(4)impart an efficient separation and strong redox abilities of photo-induced electrons and holes,which are respon-sible for the impressive photocatalytic performance.This study could motivate the ingenious design of Z-scheme heterostructures for green organic conversion based on MOFs.展开更多
Photocatalysis using polymeric carbon nitride(CN)materials is a constantly evolving field,where the variation of synthetic procedures allows the constant improvement of activity by tackling the intrinsic limitations o...Photocatalysis using polymeric carbon nitride(CN)materials is a constantly evolving field,where the variation of synthetic procedures allows the constant improvement of activity by tackling the intrinsic limitations of these materials(optical absorbance,specific surface area,charge migration,etc.).Amongst the possible photocatalytic reactions,the most popular application of CNs is the hydrogen evolution reaction(HER)from water.In this work,we design precisely-controlled carbon-doped porous CN rods with extended π-electron conjugation from supramolecular assemblies of melem and co-monomers,which partially substitute nitrogen for carbon atoms at the pyrimidine ring of the melem.Dense hydrogen bonds and good thermal stability of the melem-based supramolecular framework allow synthesizing a more ordered structure for improved charge migration;the control from the molecular level over the position of carbon-substituted nitrogen positions tailors the band alignment and photogenerated charge separation.The optimal photocatalyst shows an excellent HER rate(up to 10.16 mmol·h-1·g-1 under 100 W white light-emitting diode(LED)irradiation,with an apparent quantum efficiency of 20.0%at 405 nm,which is 23.2 times higher compared to a reference bulk CN).To fully harness the benefits of the developed metal-free CNs,selective oxidation reaction of aromatic alcohols is demonstrated with high conversion and selectivity.展开更多
Photoredox dual reaction of organic synthesis and H2 evolution opens up a novel pathway for collaboratively generating clean fuels and high-quality chemicals,providing a more effective approach of solar energy convers...Photoredox dual reaction of organic synthesis and H2 evolution opens up a novel pathway for collaboratively generating clean fuels and high-quality chemicals,providing a more effective approach of solar energy conversion.Herein,a surface defect-engineered ZnCoS/ZnCdS heterostructure with zinc blende(ZB)/wurtzite(WZ)phase junctions is synthesized for photocatalytic cooperative coupling of benzaldehyde(BAD)and H_(2) production.This surface defect-engineered ZnCoS/ZnCdS heterostructure elaborately integrates the mixed phase junction advantage of ZnCdS semiconductor and the cocatalytic function of ZnCoS possessing Zn(VZn-ZnCoS/ZnCdS)or S vacancies(VS-ZnCoS/ZnCdS).The optimum VS-ZnCoS/ZnCdS simultaneously exhibits a superior H2 production rate of 14.23 mmol h^(-1) g^(-1) accompanied with BAD formation rate of 12.29 mmol h^(-1) g^(-1) under visible-light irradiation,which is approximately two-fold greater than that of pristine ZnCdS.Under simulated sunlight irradiation(AM 1.5),VS-ZnCoS/ZnCdS achieves H2 evolution(27.43 mmol gcat^(-1) h^(-1))with 0.52%of STH efficiency,accompany with 26.31 mmol gcat^(-1) h^(-1) of BAD formation rate.The underlying solar-driven mechanism is elucidated by a series of in-situ characterization and control experiments,which reveals the synergistic effect of interfacial ZB/WZ phase junctions in ZnCdS and S vacancies of ZnCoS on enhancement of the photoredox dual reaction.The VS-ZnCoS/ZnCdS follows a predominant oxygen-centered radical integrating with carbon-centered radical pathways for BAD formation and a simultaneous electron-driven proton reduction for H_(2) production.Interestingly,the nature of surface vacancies not only facilitates the separation of photoinduced charge carriers but also able to selectively adjust the mechanism pathway for BAD production via tuning the oxygen-centered radical and carbon-centered radical formation.展开更多
Straightforward etherification of benzyl alcohols （1） via intermolecular dehydration can be efficiently catalyzed by sodium bisulfite under solvent-free conditions. In the presence of 0.3 mol% or 0.6 mol% amount of ...Straightforward etherification of benzyl alcohols （1） via intermolecular dehydration can be efficiently catalyzed by sodium bisulfite under solvent-free conditions. In the presence of 0.3 mol% or 0.6 mol% amount of sodium bisulfite, symmetric and unsymmetric ethers are prepared from the corresponding alcohols in high yields （up to 95%）. Etherification of benzhydryl alcohols is also discussed.展开更多
文摘Simultaneously utilizing photogenerated electrons and holes to convert renewable biomass and its derivatives into corresponding value‐added products and hydrogen(H_(2))is a promising strategy to deal with the energy and environmental crisis.Herein,we report a facile hydrothermal method to construct a direct Z‐scheme CdS/WO_(3) binary composite for photocatalytic coupling redox reaction,simultaneously producing H_(2) and selectively converting aromatic alcohols into aromatic aldehydes in one pot.Compared with bare CdS and WO_(3),the CdS/WO_(3) binary composite exhibits significantly enhanced performance for this photocatalytic coupled redox reaction,which is ascribed to the ex‐tended light harvesting range,efficient charge carrier separation rate and optimized redox capabil‐ity of CdS/WO_(3) composite.Furthermore,the feasibility of converting various aromatic alcohols to corresponding aldehydes coupled with H_(2) evolution on the CdS/WO_(3) photocatalyst is proved and a reasonable reaction mechanism is proposed.It is hoped that this work can provide a new insight into the construction of direct Z‐scheme photocatalysts to effectively utilize the photogenerated electrons and holes for photocatalytic coupled redox reaction.
基金This work was financially supported by the Natural Science Foundation of Jiangsu Province Youth Fund(No.BK20210628)the Scientific Research Foundation from Nanjing Forestry University.We also thank Advanced Analysis&Testing Center,Nanjing Forestry University for sample tests.
文摘Photocatalytic oxidation of aromatic alcohol into aromatic aldehyde using O_(2)has received huge atten-tion,while the reaction that occurred in ambient air is rarely studied but follows the green-chemistry principles.Herein,spindle-shaped MIL-53(Fe)-NH_(2)@ZnIn_(2)S_(4)photocatalysts with a Z-scheme heterostruc-ture were facilely developed for photocatalytic oxidation of aromatic alcohol in air under visible light.The benzyl alcohol conversion can be notably enhanced to 73%over the optimal MIL-53-NH_(2)@ZnIn_(2)S_(4)sample with a benzaldehyde production rate of 1825μmol g^(-1)h^(-1).However,in the O_(2)atmosphere,the benzyl alcohol conversion is only 56%,indicating that O_(2)is not required and has an adverse effect on the reaction.The hierarchical structure and Z-scheme heterojunction of MIL-53-NH_(2)@ZnIn_(2)S_(4)impart an efficient separation and strong redox abilities of photo-induced electrons and holes,which are respon-sible for the impressive photocatalytic performance.This study could motivate the ingenious design of Z-scheme heterostructures for green organic conversion based on MOFs.
基金grateful for the financial support from the National Natural Science Foundation of China(Nos.22078028 and 21978026)the Special Program for Introducing Foreign Talents of Changzhou(No.CQ20214032)+1 种基金the joint Israel Science Foundation-National Science Foundation of China(ISF-NSFC)(No.2969/19 and the ISF No.601/21)The authors thank Jonathan Tzadikov,Rotem Geva,Liel Abisdris,Junyi Li,and Ayelet Tashakory(Ben-Gurion University of the Negev)for technical support and Dr.Laurent Chabanne for fruitful discussion.
文摘Photocatalysis using polymeric carbon nitride(CN)materials is a constantly evolving field,where the variation of synthetic procedures allows the constant improvement of activity by tackling the intrinsic limitations of these materials(optical absorbance,specific surface area,charge migration,etc.).Amongst the possible photocatalytic reactions,the most popular application of CNs is the hydrogen evolution reaction(HER)from water.In this work,we design precisely-controlled carbon-doped porous CN rods with extended π-electron conjugation from supramolecular assemblies of melem and co-monomers,which partially substitute nitrogen for carbon atoms at the pyrimidine ring of the melem.Dense hydrogen bonds and good thermal stability of the melem-based supramolecular framework allow synthesizing a more ordered structure for improved charge migration;the control from the molecular level over the position of carbon-substituted nitrogen positions tailors the band alignment and photogenerated charge separation.The optimal photocatalyst shows an excellent HER rate(up to 10.16 mmol·h-1·g-1 under 100 W white light-emitting diode(LED)irradiation,with an apparent quantum efficiency of 20.0%at 405 nm,which is 23.2 times higher compared to a reference bulk CN).To fully harness the benefits of the developed metal-free CNs,selective oxidation reaction of aromatic alcohols is demonstrated with high conversion and selectivity.
文摘Photoredox dual reaction of organic synthesis and H2 evolution opens up a novel pathway for collaboratively generating clean fuels and high-quality chemicals,providing a more effective approach of solar energy conversion.Herein,a surface defect-engineered ZnCoS/ZnCdS heterostructure with zinc blende(ZB)/wurtzite(WZ)phase junctions is synthesized for photocatalytic cooperative coupling of benzaldehyde(BAD)and H_(2) production.This surface defect-engineered ZnCoS/ZnCdS heterostructure elaborately integrates the mixed phase junction advantage of ZnCdS semiconductor and the cocatalytic function of ZnCoS possessing Zn(VZn-ZnCoS/ZnCdS)or S vacancies(VS-ZnCoS/ZnCdS).The optimum VS-ZnCoS/ZnCdS simultaneously exhibits a superior H2 production rate of 14.23 mmol h^(-1) g^(-1) accompanied with BAD formation rate of 12.29 mmol h^(-1) g^(-1) under visible-light irradiation,which is approximately two-fold greater than that of pristine ZnCdS.Under simulated sunlight irradiation(AM 1.5),VS-ZnCoS/ZnCdS achieves H2 evolution(27.43 mmol gcat^(-1) h^(-1))with 0.52%of STH efficiency,accompany with 26.31 mmol gcat^(-1) h^(-1) of BAD formation rate.The underlying solar-driven mechanism is elucidated by a series of in-situ characterization and control experiments,which reveals the synergistic effect of interfacial ZB/WZ phase junctions in ZnCdS and S vacancies of ZnCoS on enhancement of the photoredox dual reaction.The VS-ZnCoS/ZnCdS follows a predominant oxygen-centered radical integrating with carbon-centered radical pathways for BAD formation and a simultaneous electron-driven proton reduction for H_(2) production.Interestingly,the nature of surface vacancies not only facilitates the separation of photoinduced charge carriers but also able to selectively adjust the mechanism pathway for BAD production via tuning the oxygen-centered radical and carbon-centered radical formation.
文摘Straightforward etherification of benzyl alcohols （1） via intermolecular dehydration can be efficiently catalyzed by sodium bisulfite under solvent-free conditions. In the presence of 0.3 mol% or 0.6 mol% amount of sodium bisulfite, symmetric and unsymmetric ethers are prepared from the corresponding alcohols in high yields （up to 95%）. Etherification of benzhydryl alcohols is also discussed.
